First cosmology results using type IA Supernovae from the Dark Energy Survey: Effects of chromatic corrections to supernova photometry on measurements of cosmological parameters
First cosmology results using type IA Supernovae from the Dark Energy Survey: Effects of chromatic corrections to supernova photometry on measurements of cosmological parameters
ABSTRACT
Calibration uncertainties have been the leading systematic uncertainty in recent analyses using type Ia Supernovae (SNe Ia) to measure cosmological parameters. To improve the calibration, we present the application of Spectral Energy Distribution (SED)-dependent “chromatic corrections" to the supernova light-curve photometry from the Dark Energy Survey (DES). These corrections depend on the combined atmospheric and instrumental transmission function for each exposure, and they affect photometry at the 0.01 mag (1%) level, comparable to systematic uncertainties in calibration and photometry. Fitting our combined DES and low-z SN Ia sample with Baryon Acoustic Oscillation (BAO) and Cosmic Microwave Background (CMB) priors for the cosmological parameters m (the fraction of the critical density of the universe comprised of matter) and w (the dark energy equation of state parameter), we compare those parameters before and after applying the corrections. We find the change in w and m due to not including chromatic corrections are 􀀀0:002 and 0:000, respectively, for the DES-SN3YR sample with BAO and CMB priors, consistent with a larger DES-SN3YR-like simulation, which has a w-change of 0:0005 with an uncertainty of 0:008 and an m change of 0:000 with an uncertainty of 0:002 . However, when considering samples on individual CCDs we find large redshift-dependent biases ( 0:02 in distance modulus) for supernova distances.
Key words: cosmology: dark energy, cosmology: observations, supernovae, techniques: photometric
cosmology: dark energy, cosmology: observations, supernovae, techniques: photometric
5329-5344
Sullivan, Mark
2f31f9fa-8e79-4b35-98e2-0cb38f503850
June 2019
Sullivan, Mark
2f31f9fa-8e79-4b35-98e2-0cb38f503850
DES Collaboration
(2019)
First cosmology results using type IA Supernovae from the Dark Energy Survey: Effects of chromatic corrections to supernova photometry on measurements of cosmological parameters.
Monthly Notices of the Royal Astronomical Society, 485 (4), .
(doi:10.1093/mnras/stz619).
Abstract
ABSTRACT
Calibration uncertainties have been the leading systematic uncertainty in recent analyses using type Ia Supernovae (SNe Ia) to measure cosmological parameters. To improve the calibration, we present the application of Spectral Energy Distribution (SED)-dependent “chromatic corrections" to the supernova light-curve photometry from the Dark Energy Survey (DES). These corrections depend on the combined atmospheric and instrumental transmission function for each exposure, and they affect photometry at the 0.01 mag (1%) level, comparable to systematic uncertainties in calibration and photometry. Fitting our combined DES and low-z SN Ia sample with Baryon Acoustic Oscillation (BAO) and Cosmic Microwave Background (CMB) priors for the cosmological parameters m (the fraction of the critical density of the universe comprised of matter) and w (the dark energy equation of state parameter), we compare those parameters before and after applying the corrections. We find the change in w and m due to not including chromatic corrections are 􀀀0:002 and 0:000, respectively, for the DES-SN3YR sample with BAO and CMB priors, consistent with a larger DES-SN3YR-like simulation, which has a w-change of 0:0005 with an uncertainty of 0:008 and an m change of 0:000 with an uncertainty of 0:002 . However, when considering samples on individual CCDs we find large redshift-dependent biases ( 0:02 in distance modulus) for supernova distances.
Key words: cosmology: dark energy, cosmology: observations, supernovae, techniques: photometric
Text
stz619
- Accepted Manuscript
Available under License Other.
More information
Accepted/In Press date: 26 February 2019
e-pub ahead of print date: 5 March 2019
Published date: June 2019
Keywords:
cosmology: dark energy, cosmology: observations, supernovae, techniques: photometric
Identifiers
Local EPrints ID: 429081
URI: http://eprints.soton.ac.uk/id/eprint/429081
ISSN: 1365-2966
PURE UUID: 2a82aa0e-2fe1-4b75-8376-8f72a088a967
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Date deposited: 20 Mar 2019 17:30
Last modified: 16 Mar 2024 04:12
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Corporate Author: DES Collaboration
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